Thomas Bräunl

Evaluation of real-time physics simulation systems

We present a qualitative evaluation of a number of free publicly available physics engines for simulation systems and game development. A brief overview of the aspects of a physics engine is presented accompanied by a comparison of the capabilities of each physics engine. Aspects that are investigated the accuracy and computational efficiency of the integrator properties, material properties, stacks, links, and collision detection system.

Symmetry-based monocular vehicle detection system

In this paper, we describe the development of a symmetry-based vehicle detection system. The system uses a single forward looking camera to capture the road scene. Vehicles are detected based on their edges and symmetrical characteristics. A method to extract the symmetric regions in the image using a multi-sized window and clustering technique is introduced. We hypothesize the vehicle’s locations in the image from the detected symmetric regions and the regions are then further processed to enhance their symmetrical edges. A bounding box of a vehicle is detected from the projection maps of the enhanced vertical and horizontal edges. The hypothesized vehicles are then verified using a two-class classifier, which consists of an edge oriented histogram (EOH) feature extractor and a support vector machine (SVM). Once a vehicle is verified, a tracking process based on a Kalman filter and a reliability point system is used to track the movement of the vehicle in consecutive video frames. The system was successfully implemented and tested on a standard PC. Experimental results on live video feed and pre-recorded video sequences for various road scenes showed that the system is able to detect multiple vehicles in real time.

Research relevance of mobile robot competitions

A look at the scope, rules, robot designs, and robot evolution over the years for three of what the authors suggest are most prominent event series; the Micromouse Contest, the AAAI Mobile Robot Competition, and RoboCup Robot Soccer.

Impact of Ambulance Dispatch Policies on Performance of Emergency Medical Services

In ambulance location models, fleet size and ambulance location sites are two critical factors that emergency medical service (EMS) managers can control to ensure efficient delivery of the system. The ambulance relocation and dispatch policies that are studied in dynamic ambulance relocation models also significantly contribute to improving the response time of EMS. In this paper, we review dynamic ambulance relocation models from the perspective of dispatch policies. The connection between the reviewed ambulance dispatch policies and real-life policies is highlighted. Our ambulance model is based on the modified maximal covering location problem (MCLP). It is used to examine the commonly used dispatch policy and the proposed method of free-ambulance exploitation to further improve urgent call response time. Simulation results show that the proposed method can reduce the response time of urgent calls, especially during low-ambulance-supply period. We also compared the performance of EMS with and without reroute-enabled dispatch.

Parallel image processing

1 Introduction.- 2 Point Operators.- 3 Local Operators.- 4 Edge Detection.- 5 Skeletonizing.- 6 Morphological Operators.- 7 Segmentation.- 8 Corner Detection.- 9 Hough Transform.- 10 Fourier Transform.- 11 Texture Recognition.- 12 Stereo Image Processing.- 13 Analysis of Image Sequences.- A The Parallel Programming Language Parallaxis.- B Parallaxis-III Syntax.- C Programming Tools.- D Vision Library.- E References.

Flexible wireless communication network for mobile robot agents

For intelligent robots in a multi‐agent system communication is essential for cooperative behavior. Here we describe the explicit communication between individual robots acting as team members of a RoboCup team playing soccer. The robots are based on the EyeBot platform. An overview of communication systems being published and a discussion of their advantages and drawbacks is followed by an introduction into multi‐agent systems and the problems we faced applying them to the task of playing soccer. Then we describe the wireless communication network in detail including the EyeBot platform, message structures, self‐configuration and error recovery. The communication allows transmission of messages between individuals, broadcasts and communication with a remote computer workstation. The communication system is a layer beneath the multi‐robot console, which is the user interface, and above the EyeBot hardware.

Progress in Robotics

This volume is a selection of papers of six international conferences that are held under the umbrella of the 12th FIRA RoboWorld congress, in Incheon, Korea, August 16-18, 2009. From the 115 contributed papers 44 papers are included in the volume, which is organized into 6 sections: humanoid robotics, human robot interaction, education and entertainment, cooperative robotics, robotic system design, and learning, optimization, communication. The volume is intended to provide readers with the recent technical progresses in robotics, human robot interactions, cooperative robotics and the related fields.

Dynamic population variation in genetic programming

Three innovations are proposed for dynamically varying the population size during the run of the genetic programming (GP) system. These are related to what is called Dynamic Population Variation (DPV), where the size of the population is dynamically varied using a heuristic feedback mechanism during the execution of the GP with the aim of reducing the computational effort compared with Standard Genetic Programming (SGP). Firstly, previously developed population variation pivot functions are controlled by four newly proposed characteristic measures. Secondly, a new gradient based pivot function is added to this dynamic population variation method in conjunction with the four proposed measures. Thirdly, a formula for population variations that is independent of special constants is introduced and evaluated. The efficacy of these innovations is examined using a comprehensive range of standard representative problems. It is shown that the new ideas do have the capacity to provide solutions at a lower computational cost compared with standard genetic programming and previously reported algorithms such as the plague operator and the static population variation schemes previously introduced by the authors.

Large-scale multi-robot mapping in MAGIC 2010

We describe a large-scale decentralised multi-robot mapping system that outputs globally optimised metric maps in real-time. The mapping system was used by team WAMbot in the finals of the Multi-Autonomous Ground-robotics International Challenge (MAGIC 2010). Research contributions include a novel large-scale multi-robot graph-based non-linear map optimisation approach, a hybrid decentralised and distributed mapping system and novel graphics processing unit (GPU) based approaches for accelerating intensive map matching and fusion operations. Our mapping system scales linearly with map size and on commodity hardware can easily map a 500m×500m urban area. We demonstrate robust, highly efficient and accurate mapping results from two different fleets of mobile robots. Videos, maps and timing results from the MAGIC 2010 challenge are presented.

Market-based approach for multi-team robot cooperation

The scalability of market-based approaches in multi-robot system coordination enables an assigned task to be decomposed into subcomponents achievable by individuals or subteams within the team. However, in some potential multi-robot system applications, particularly search and rescue operations, this can involve deployment of multiple teams of robots from different parties to work side by side. Each team of robots is independently managed by its operator. A loose collaboration among teams of robots is needed to increase the efficiency of a task completion. This work presents a variant architecture of multi-robot systems using Contract Net Protocol to address the coordination among multiple teams of robots. The system is named a multi-team robot system. It places emphasis on a teams data security in communication where each team operates on a respective communication network while maintaining their collaboration. The method of task coordination is explained in detail and verified on a physical mobile robot platform.